Pastes for photoelectric conversion layers of X-ray detectors, X-ray detectors and methods of manufacturing the same

Abstract

A paste for a photoelectric conversion layer used in an X-ray detector includes photoconductive particles, an organic polymer binder, a first organic solvent to dissolve the organic polymer binder, and a second organic solvent. The second organic solvent has a boiling point in a range of between about 150° C. and about 210° C., inclusive.

What is claimed is: 
     
       1. A paste for a photoelectric conversion layer, the paste comprising:
 photoconductive particles; 
 an organic polymer binder; 
 a first organic solvent to dissolve the organic polymer binder; and 
 a second organic solvent having a boiling point in a range of between about 150° C. and about 210° C., inclusive, the second organic solvent different from the first organic solvent. 
 
     
     
       2. The paste of  claim 1 , wherein the photoconductive particles include one of HgI 2  particles, PbI 2  particles, BiI 3  particles, TlBr particles, PbO particles, CdTe particles, CdZnTe particles, and any mixtures thereof. 
     
     
       3. The paste of  claim 2 , wherein the photoconductive particles include HgI 2  particles. 
     
     
       4. The paste of  claim 1 , wherein the organic polymer binder includes one of a polyvinyl butyral (PVB) resin, an acryl resin, a phenoxy resin, a polyester resin, a polyvinyl formal resin, a polyamide resin, a polystyrene resin, a polycarbonate resin, a polyvinyl acetate resin, a polyurethane resin, an epoxy resin, and any mixtures thereof. 
     
     
       5. The paste of  claim 4 , wherein the organic polymer binder includes one of a polyvinyl butyral (PVB) resin, an acryl resin, a phenoxy resin, and any mixtures thereof. 
     
     
       6. The paste of  claim 1 , wherein the first organic solvent dissolves the organic polymer binder to form a binder solution. 
     
     
       7. The paste of  claim 1 , wherein the first organic solvent includes dipropylene glycol monomethyl ether (DPGME). 
     
     
       8. The paste of  claim 1 , wherein the second organic solvent includes one of butyl cellosolve acetate (BCeA), KOCOSOL, butyl cellosolve (BC), ethyl 3-ethoxypropionate (EEP), and any mixtures thereof. 
     
     
       9. The paste of  claim 1 , wherein an amount of the organic polymer binder is in a range of between about 2.5 and about 15, inclusive, parts by weight with respect to about 100 parts by weight of the photoconductive particles. 
     
     
       10. The paste of  claim 1 , wherein an amount of the first organic solvent is in a range of between about 3 wt % and about 10 wt %, inclusive, with respect to a total weight of the paste. 
     
     
       11. The paste of  claim 10 , wherein an amount of the second organic solvent is in a range of between about 5 wt % and about 40 wt %, inclusive, with respect to the total weight of the paste. 
     
     
       12. The paste of  claim 1 , wherein an amount of the second organic solvent is in a range of between about 5 wt % and about 40 wt %, inclusive, with respect to a total weight of the paste. 
     
     
       13. An X-ray detector comprising:
 a readout device on a substrate; and 
 a photoelectric conversion layer on the readout device, the photoelectric conversion layer being formed from the paste of  claim 1 . 
 
     
     
       14. The X-ray detector of  claim 13 , wherein the readout device includes a switching device and a charge storage device electrically connected by a pixel electrode. 
     
     
       15. The X-ray detector of  claim 14 , wherein the switching device is a thin film transistor device and the charge storage device is a capacitor. 
     
     
       16. A method of manufacturing a photoelectric conversion layer, comprising:
 coating a paste on a substrate, the paste including photoconductive particles, an organic polymer binder, a first organic solvent to dissolve the organic polymer binder, and a second organic solvent having a boiling point in a range of between about 150° C. and about 210° C., inclusive, the second organic solvent different from the first organic solvent; and 
 heat treating the substrate with the paste coated thereon. 
 
     
     
       17. The method of  claim 16 , wherein the substrate and the paste coated thereon are heat treated at a temperature in a range of between about 50° C. and about 80° C., inclusive. 
     
     
       18. The method of  claim 16 , wherein the photoconductive particles include one of HgI 2  particles, PbI 2  particles, BiI 3  particles, TlBr particles, PbO particles, CdTe particles, CdZnTe particles, and any mixtures thereof. 
     
     
       19. The method of  claim 16 , wherein the organic polymer binder includes one of a polyvinyl butyral (PVB) resin, an acryl resin, a phenoxy resin, a polyester resin, a polyvinyl formal resin, a polyamide resin, a polystyrene resin, a polycarbonate resin, a polyvinyl acetate resin, a polyurethane resin, an epoxy resin, and any mixtures thereof. 
     
     
       20. The method of  claim 16 , wherein the first organic solvent includes dipropylene glycol monomethyl ether (DPGME). 
     
     
       21. The method of  claim 16 , wherein the second organic solvent includes one of butyl cellosolve acetate (BCeA), KOCOSOL, butyl cellosolve (BC), ethyl 3-ethoxypropionate (EEP), and any mixtures thereof. 
     
     
       22. The method of  claim 16 , wherein an amount of the organic polymer binder is in a range of between about 2.5 and about 15, inclusive, parts by weight with respect to about 100 parts by weight of the photoconductive particles. 
     
     
       23. The method of  claim 16 , wherein the heat treating removes the second organic solvent from the coated paste. 
     
     
       24. The method of  claim 16 , wherein an amount of the first organic solvent is in a range of between about 3 wt % to and about 10 wt %, inclusive, with respect to a total weight of the paste. 
     
     
       25. The method of  claim 16 , wherein an amount of the second organic solvent is in a range of between about 5 wt % to and about 40 wt %, inclusive, with respect to the a total weight of the paste.